The invention relates to a shaving razor and a blade unit therefor with an improved guard.
Shaving razors often consist of a handle and a replaceable cartridge in which one or more blades are mounted in a plastic housing. U.S. Pat. No. 5,918,369 describes a shaving razor including a replaceable cartridge that has a blade unit that is pivotally connected to an interconnect member that is in turn connected to a handle. The blade unit includes a guard having resilient fins in front of the blades to engage the skin surface and a lubricating strip behind the blades.
In one aspect, the invention features, in general, a shaving razor blade unit that has a plurality of blades and a guard that includes two groups of rows of elongated, elastomeric fins arranged generally parallel to the cutting edges of the blades. The first group of fins has tips with increasing elevation with respect to a plane passing through the cutting edges, and the second group of fins has tips of generally uniform position relative to the plane.
In another aspect, the invention features, in general, a shaving razor blade unit that has a plurality of blades and a guard that includes at least six rows of elongated, elastomeric fins arranged generally parallel to the cutting edges of the blades.
In another aspect, the invention features, in general, a shaving razor blade unit that has a plurality of blades and a guard that includes at least five rows of elongated, elastomeric fins that are arranged generally parallel to the cutting edges of the blades and generally increase in elevation with respect to a plane passing through the cutting edges of the blades in going from fins further from the blades to fins closer to the blades.
In another aspect, the invention features, in general, shaving razor blade unit that has a plurality of blades and a guard that includes a plurality of rows of elongated, elastomeric fins that are arranged generally parallel to the cutting edge. The fins converge from a base portion to a tip portion at an included angle of less than 14 degrees.
Particular embodiments of the invention may include one or more of the following features. In embodiments with two groups of fins, each group preferably includes at least three fins and most preferably includes about five fins. Some of the fins have tips above the plane passing through the cutting edges, and some of the fins have tips below the plane. There preferably are at least 6 rows of fins on the guard, more preferably about 8 rows of fins, and most preferably about 10 rows of fins. The tips preferably have a height between 0.4 mm and 0.8 mm., most preferably between 0.6 mm and 0.7 mm. The fins preferably have an included angle less than 14 degrees, most preferably about 12 degrees. The distance from the first fin to the last fin preferably is between 2.0 mm and 3.5 mm. The blades are preferably movably mounted with respect to said housing, and the blade unit is connected to a pivotal structure to permit the blades in to pivot with respect to a handle. The fins are made of material having a Shore A hardness between 30 and 60 (preferably between) 40 and 50.
In another aspect, the invention features a shaving razor including a handle and a blade unit as already described connected to handle.
Embodiments of the invention may include one or more of the following advantages. The fins tend to stimulate and stretch the skin in front of the blades, tending to improve comfort and proper positioning of the skin for cutting of hairs. The increasing elevation of fins tends to gradually increase skin contact and causes the tips to conform to the skin flow during shaving. The narrow included angle profile improves fin flexibility, which helps to stretch the skin, thereby setting up the hairs for improved cutting. The use of a large number of fins improves skin engagement.
Other advantages and features of the invention will be apparent from the following description of a preferred embodiment thereof.